King's College London, sometimes known as King's or KCL and formerly known as King's College, London, is a constituent college of the federal University of London and a public research university with headquarters in London, United Kingdom. Given that it was established by King George IV and the Duke of Wellington in 1829 and obtained its royal charter the same year, it is undoubtedly the third-oldest university in England. With roots dating back to 1173 and a medical school founded in 1550, King's College London School of Medicine's St. Thomas' Hospital is today a teaching hospital. In 1836, King's became one of the University of London's two original colleges. The Institute of Psychiatry, Queen Elizabeth College, Chelsea College of Science and Technology, the United Medical and Dental Schools of Guy's and St. Thomas' Hospitals, and Florence Nightingale School of Nursing and Midwifery are just a few of the mergers that have helped it expand (in 1998).